Method of producing diazo-amino compounds



Patented cr. 11,193s c 7' Q 7 2 ,133,037

*- omrfso STATES oEFicE METHODOF rRoDuciNG-nrmmm 0 Y r COMPQUNDS, c V ,Wendell:W.- Moyer, Y assign or to The. Solvay Process Company, New York, NI Y., a corporation of New .I'f

-l\ToDra.wing.' Application January 3,1936," "j Serial No.157,366ii' i I v ;;i'.. 1 This invention relates to a method for the ,amu eandpne moi in 300. molsof water, preparation of diazo-amino compounds from primaintained at15 {C., 1.17 mols of NOCl :were mary amines. a passedi'atthe ratebftqfiflimol.penhour. During The invention has for its object the preparation the-addition the: solutionewas. subJected to conof diazo-amino compounds in a simpler, more tinuous agitation to eflect thorough admixture efiicient, and more inexpensive manner than and prevent localized overheating. Solid diazoheretofore accomplished. amino-benzene v In the past diazo-amino compounds have been prepared from primary aromatic amines by ef- C N=NNC 1 fecting diazotizlng of the amine with sodium 10 n nitritein acid solution, and treating the diazonium salt with an amine to produce the diazoas formed a a precipitate during the reaction amino compound. and; upon completion of the NOCl addition, was In accordance With the Present invention I separated from the liquid by filtration. The solid h v found that pr r m m n may product thus obtained represented a yield of 80% 15 be reacted with nitrosyl chloride in the presence based u on-the aniline employed. In lieu of NH: of a base to give directly a high yield of diazoany other suitable base may be employed, for amino product. instanceNaOH or NazCOa.

Any suitable base may be employed for the Example 2.-One mol of NOCl was added at p rp f the pre t nv i Thua m-l a now rateor 0.2 mol per hour with vigorous 20 a, sodium d x d s um ca bo at r striring to '7 mols of aniline maintained at 20 c. lime y be used ctorily. I have found In this case the excess aniline preserved the that an excess of the amine to be employed as alkalinity of the solution during the reaction. the initial material may serve to advantage in The resulting mixture, which consisted of a this p y W ere a base other than the solution of diazo-amino-benzene and aniline hy- 25 amine i mp y t mine ma be treated with drochloride in aniline, was then gradually warmed around half a mol of NOCl per mol of amine. to 40 to 50 C. and allowed to cool slowly to 20 The amine y be d ve in a y uitab e C..over a period of 17 hours. The yield of aminov nt nd he ni r yl chl d m y be passed azo-benzene was 86%, based on the N001 used.

thereinto or the nitrosyl chloride and the amine The molar or formula ratio of nitrosyl chloride 30 may be simultaneously introduced into the $01-- to amine should not be in great excess of. one vent. The amount of base present should be to two as the excess NOClmay yield a diazonium suflicient to maintain the solution neutral or salt instead of the desired diazo-amino compound. slightly alkaline during the reaction. The base A ratio as .high as 1.3 to 2 may be employed,

y be added entirely at e beg ning of the however, without formation of asubstantial quan- 35 reaction or may be added gradually during the my of the diazonium salt. The ratio may be addition of NOCl. Where theamine is employed] much less than one to two as in the case .where as the base, it is of course necessary to increase the amine is employed to bind hydrochloric acid, the amount thereof so thatin additionto two but where another base, say an inorganic'base,

40 mols of amine for each molof NOClemployed, ;is employed ior'this purpose, it is desirable to 40 sufiicient excess amine is. present to form with employ an NOCI: amine ratio of at least liberated hydrochloric acidthe amine hydrochlo- The temperature of the reaction mixture is ride. This latter modification of the invention, preferably maintained low, 1. e. is not allowed-to wherein an excess of the amine is employed as rise substantially aboveabout 20 C., in order to the base, is especiallyapplicable to the preparaprevent premature rearrangement'and formation 45 tion of amino azo compounds since the diazoof undesired by-products. amino compound in admixture with the amine I claim: hydrochloride resulting from the treatment with 1. The method of preparing a diazo-amino nitrosyl ChlOride may be converted to the correcompoundfrom a primary aromatic amine, which sponding amino azo compound merely by warmcomprises introducing NOCl into intimate con- 50 ing the mixture to a temperature around 40 C. tact with the arylamine in a formula ratio of or higher. not more than about 1.3 to 2v and maintaining The following specific examples. will serve to suflicient base present to-bind hydrochloric acid illustrate the present invention: formed during the reaction.

Example 1.-Into a solution of two molsot 2. The method of preparing a dlazo-amino 55 7 ing the reaction.

3. The method of preparing adiazo-amino compound from a'primary arylamine, which comprises introducing about mol of NOCl into a I solution of a mol of the primary arylamine and molof ammonia at a temperature not in excess of about 20 C.

4. The method of preparing a diazo-amino' compound from a primary arylamine, which com.- prises introducing NOCl into intimate contact; with the primary aryiamine and maintaining suf-e ficient' of the primary arylamine in excess of one mol arylamine to /2 mol NOCI to react with about 7 mols of aniline at a temperature not 5. The'method or preparing a diazo-amino .compound'from aprimary arylamine, which com- ..prises introducing about .onemoi oi- NOClv into iintimatecontactwith about fZmols of the primary amineat a temperature not exceeding about 20C.

hydrochloric acid formed during the reaction.

6'. The method of preparing an amino-azo compound from a primary arylamine, which comprises introducing NOCI into intimate contact with the primary aryiamine at a temperaturenot exceeding about 26 C. and maintaining sufiicient of the primary arylamine in excess of one mol arylamine to A- mol N001 to react with hydrochloric acid formed during the reaction and heatingthe resultant reaction'mixture to a temperature above about 40 C. 7 7. The method. of preparing diazo-amino-ben- 'z ene fromaniline, which comprises introducing about l mol of NOCi into intimate contact with about 7 mols of aniline at a temperature not exceeding abou't 20 C.

' 8. 'The method of preparing amino-azo-benzenemfrom: anilineywhich comprises introducing about 1 mol of NOCl into intimate contact with exceeding about 20 C'., and heating, the resultant :reactionfmixture toa temperature above about WENDELL W. MOYER. V 

